Prognostic Meteorological Discussion
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FXAK02 KWNH 082018
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ALASKA EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
318 PM EST THU DEC 08 2016

VALID 12Z MON DEC 12 2016 - 12Z FRI DEC 16 2016

THE OVERALL SURFACE PATTERN HIGHLIGHTS HIGH PRESSURE FOR AK...
MEANING A MOSTLY STABLE MEDIUM RANGE PERIOD WITH LITTLE OR MINIMAL
PRECIPITATION FOR THE MAJORITY OF THE STATE. AN ELONGATED UPPER
RIDGE OVER THE STATE ON MON WILL BE SQUEEZED BY A SHORT WAVE
TRACKING FROM THE ARCTIC OCEAN TO NW CANADA... WHILE A DYNAMIC
IMPULSE NEAR THE BEARING SEA SLIDES UP THE ALEUTIAN CHAIN. THEN ON
TUES... THIS RIDGE BECOMES SOMEWHAT DIRTY WITH ENERGY FROM THE
BEARING SEA SHORT WAVE TRACKING TOWARD THE GULF OF AK... WHILE
SHARP UPPER RIDGING DEVELOPS UPSTREAM ACROSS THE ALEUTIANS AND
NWRN AK. THIS UPSTREAM RIDGE THEN BUILDS ACROSS THE ENTIRE STATE
ON WED VIA GFS/CANADIAN BEFORE UPSTREAM NWRN PAC DYNAMICS KNOCK
DOWN THE NRN PERIPHERY OF THE RIDGE ON THURS. ITS THE LAST TWO
DAYS... THURS/FRI NEXT WEEK... WHERE THE MEANS WILL LIKELY BE USED
DUE TO THE VARIETY OF OPERATIONAL SOLUTIONS. DESPITE ALL OF THIS
OCCURRING ALOFT... PRETTY MUCH COLD HIGH PRESSURE REMAINS IN
CONTROL FOR AK. 850 MB TEMP ANOMALIES WILL REMAIN NEAR AVG OR
NEUTRAL FOR THE PERIOD OTHER THAN THE ALEUTAINS VIA GEFS MEAN. THE
MOST SIGNIFICANT PRECIP CHANCES WILL OCCUR NEAR THE ALEUTIAN
CHAIN... AS DEEP SRLY WARM ADVECTION AHEAD OF THE LARGE LOW
PRESSURE SYSTEM OVER THE NWRN PAC ATTEMPTS TO REACH THE STATE. WPC
STARTED OFF WITH A 12Z GFS AND 00Z/08 CANADIAN INTO NEXT WED AND
WENT PREDOMINATELY 00Z ECMWF MEAN AND 06Z GEFS MEAN NEXT
THURS/FRI.

MUSHER

$$





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